Syngeneic antisera against tumors, induced by ultraviolet light and chemical carcinogens, are used to extract and characterize the relevant tumor-associated antigens. Radiolabeled tumors from tissue culture are subjected to non-ionic detergents and the soluble extracts fractionated by absorption to and elution from Lens culinaris columns. This is followed by formation of antigen-antibody (anti-tumor) complexes which are then extracted on immunosorbent columns. PAGE and two-dimensional EP-IEF with fluorography identify and compare extracts in search of proposed host components or epitopes in tumor-host associated antigens. Hybridomas will be developed to supply larger quantities of antibody of various restricted specificities such as for tumor specific, tumor associated and common antigens.